PANEL PERFORMANCE AND NUMBER OF EVALUATIONS IN A DESCRIPTIVE SENSORY STUDY

The assessor performance is a key point in a sensory evaluation. In particular, at the end of a session, a decrease of the performance can be feared. We propose to analyze this performance with various criteria: usual ones as the main product effect or the error variance; a new one measuring the perceived products variability. The performance can then be studied all along the session from two points of view: in taking into account the only products tested at a given instant (named instantaneous); in taking into account all the products tested up to a given instant (named cumulative). In the presented example, in spite of the large number of products successively tested by each assessor, the instantaneous performance of the panel shows no significant deterioration. Furthermore, when the number of products tested by each assessor increases, more significant product effects can be obtained thanks to the accumulation of the amount of data. This shows that the number of products that can be reasonably studied by one assessor during one session is generally underestimated.     

Theory and practice of combining coagulant fixation and microwave histoprocessing

The German, F. Blum, introduced formalin as a fixative in 1893. Formalin rapidly became popular for hardening and preserving gross human and animal specimens. As a result, microscopy for diagnostic pathology by combining paraffin embedding and formalin fixation was developed. Alcohol-based fixatives have coagulation of proteins as their main preservative effect. Because there is no cross-linking, immunostaining is not compromised, and DNA and RNA is not damaged. Ethyl alcohol was used by Dutch scientists of the 18th century, but was replaced by the cheaper formalin. Addition of low molecular weight polyethylene glycol (PEG) optimized the coagulant fixative, Kryofix. The polyethylene glycol prevents excessive hardening and enhances the speed of coagulation of proteins. Kryofix was used on a large scale for skin biopsies in Leiden between 1987 and 2001. DNA preservation by the formulated coagulant fixative, BoonFix, is related to the concentration of ethyl alcohol, PEG and acetic acid. BoonFix has been used since 2004 in Leiden for over 40,000 diagnostic skin biopsies and more than 100,000 cervical samples. A literature review and three decades of experience with coagulant, formalin-free fixatives in pathology suggest that when health authorities realize that formalin invalidates expensive tests, it might eventually be eliminated legislatively from diagnostic pathology. Finally, coagulant fixation is optimal for microwave histoprocessing where ethyl alcohol is followed by isopropanol.     

DNA‐based discrimination between the sibling species Aphis gossypii Glover and Aphis frangulae Kaltenbach

Abstract Morphologically similar species occur in various groups of insects, including aphid pests. In Europe, Aphis frangulae Kaltenbach and Aphis gossypii Glover (sometimes considered as subspecies) are differentiated usually on the basis of life cycle and host plant. We used a sexual population of A. frangulae collected on the primary host and samples of A. gossypii collected on cucurbits or cotton for the development of molecular markers. DNA sequence data for the gene encoding cytochrome b and for the barcode region of cytochrome oxidase I, as well as a length polymorphism for an intron in the sodium channel para‐type gene discriminated unambiguously between the two taxa. These markers were also used as identification keys for aphids collected on crops belonging to the Solanaceae. The cytochrome b marker differentiates host‐related Aphis gossypii haplotypes, and the para‐type gene intron might be suitable for the resolution of taxonomic problems in other aphid species complexes.     

Computer simulation studies of microcrystalline cellulose Ibeta

Molecular mechanics (MM) simulations have been used to model two small crystals of cellulose Ibeta surrounded by water. These small crystals contained six different extended surfaces: (110), (11 0), two types of (100), and two types of (010). Significant changes took place in the crystal structures. In both crystals there was an expansion of the unit cell, and a change in the gamma angle to almost orthogonal. Both microcrystals developed a right-hand twist of about 1.5 degrees per cellobiose unit, similar to the twisting of beta-sheets in proteins. In addition, in every other layer, made up of the unit cell center chains, a tilt of the sugar rings of 14.8 degrees developed relative to the crystal plane as a result of a transition of the primary alcohol groups in these layers away from the starting TG conformation to GG. In this conformation, these groups made interlayer hydrogen bonds to the origin chains above and below. No change in the primary alcohol conformations or hydrogen-bonding patterns in the origin chain layers was observed. Strong localization of the adjacent water was found for molecules in the first hydration layer of the surfaces, due to both hydrogen bonding to the hydroxyl groups of the sugar molecules and also due to hydrophobic hydration of the extensive regions of nonpolar surface resulting from the axial aliphatic hydrogen atoms of the 'tops' of the glucose monomers. Significant structuring of the water was found to extend far out into the solution. It is hypothesized that the structured layers of water might present a barrier to the approach of cellulase enzymes toward the cellulose surfaces in enzyme-catalyzed hydrolysis, and might inhibit the escape of soluble products, contributing to the slow rates of hydrolysis observed experimentally. Since the water structuring is different for the different surfaces, this might result in slower hydrolysis rates for some surfaces compared to others.     

Improved ethanol yield and reduced minimum ethanol selling price (MESP) by modifying low severity dilute acid pretreatment with deacetylation and mechanical refining: 2) Techno-economic analysis

ABSTRACT: BACKGROUND: Our companion paper discussed the yield benefits achieved by integrating deacetylation, mechanical refining, and washing with low acid and low temperature pretreatment. To evaluate the impact of the modified process on the economic feasibility, a techno-economic analysis (TEA) was performed based on the experimental data presented in the companion paper. RESULTS: The cost benefits of dilute acid pretreatment technology combined with the process alternatives of deacetylation, mechanical refining, and pretreated solids washing were evaluated using cost benefit analysis within a conceptual modeling framework. Control cases were pretreated at much lower acid loadings and temperatures than used those in the NREL 2011 design case, resulting in much lower annual ethanol production. Therefore, the minimum ethanol selling prices (MESP) of the control cases were $0.41-$0.77 higher than the $2.15/gallon MESP of the design case. This increment is highly dependent on the carbohydrate content in the corn stover. However, if pretreatment was employed with either deacetylation or mechanical refining, the MESPs were reduced by $0.23-$0.30/gallon. Combing both steps could lower the MESP further by $0.44 ~ $0.54. Washing of the pretreated solids could also greatly improve the final ethanol yields. However, the large capital cost of the solid--liquid separation unit negatively influences the process economics. Finally, sensitivity analysis was performed to study the effect of the cost of the pretreatment reactor and the energy input for mechanical refining. A 50% cost reduction in the pretreatment reactor cost reduced the MESP of the entire conversion process by $0.11-$0.14/gallon, while a 10-fold increase in energy input for mechanical refining will increase the MESP by $0.07/gallon. CONCLUSION: Deacetylation and mechanical refining process options combined with low acid, low severity pretreatments show improvements in ethanol yields and calculated MESP for cellulosic ethanol production.     

Paradigmatic status of an endo- and exoglucanase and its effect on crystalline cellulose degradation

Background

Presently, different studies are conducted related to the topic of biomass potential to generate through anaerobic fermentation process alternative fuels supposed to support the existing fossil fuel resources, which are more and more needed, in quantity, but also in quality of so called green energy. The present study focuses on depicting an optional way of capitalizing agricultural biomass residues using anaerobic fermentation in order to obtain biogas with satisfactory characteristics.. The research is based on wheat bran and a mix of damaged ground grains substrates for biogas production.

Results

The information and conclusions delivered offer results covering the general characteristics of biomass used , the process parameters with direct impact over the biogas production (temperature regime, pH values) and the daily biogas production for each batch relative to the used material.

Conclusions

All conclusions are based on processing of monitoring process results , with accent on temperature and pH influence on the daily biogas production for the two batches. The main conclusion underlines the fact that the mixture batch produces a larger quantity of biogas, using approximately the same process conditions and input, in comparison to alone analyzed probes, indicating thus a higher potential for the biogas production than the wheat bran substrate. Adrian Eugen Cioabla, Ioana Ionel, Gabriela-Alina Dumitrel and Francisc Popescu contributed equally to this work     

Do communication training programs improve students' communication skills? - a follow-up study

ABSTRACT: BACKGROUND: Although it is taken for granted that history-taking and communication skills are learnable, this learning process should be confirmed by rigorous studies, such as randomized pre- and post-comparisons. The purpose of this paper is to analyse whether a communication course measurably improves the communicative competence of third-year medical students at a German medical school and whether technical or emotional aspects of communication changed differently. METHOD: A sample of 32 randomly selected students performed an interview with a simulated patient before the communication course (pre-intervention) and a second interview after the course (post-intervention), using the Calgary-Cambridge Observation Guide (CCOG) to assess history taking ability. RESULTS: On average, the students improved in all of the 28 items of the CCOG. The 6 more technically-orientated communication items improved on average from 3.4 for the first interview to 2.6 in the second interview (p < 0.0001), the 6 emotional items from 2.7 to 2.3 (p = 0.023). The overall score for women improved from 3.2 to 2.5 (p = 0.0019); male students improved from 3.0 to 2.7 (n.s.). The mean interview time significantly increased from the first to the second interview, but the increase in the interview duration and the change of the overall score for the students' communication skills were not correlated (Pearson's r = 0.03; n.s.). CONCLUSIONS: Our communication course measurably improved communication skills, especially for female students. These improvements did not depend predominantly on an extension of the interview time. Obviously, "technical" aspects of communication can be taught better than "emotional" communication skills.     

Mites as biological tags of their hosts

Movements and spatial distribution of host populations are expected to shape the genetic structure of their parasite populations. Comparing the genetic patterns of both interacting species may improve our understanding of their evolutionary history. Moreover, genetic analyses of parasites with horizontal transmission may serve as indicators of historical events or current demographic processes that are not apparent in the genetic signature of their hosts. Here, we compared mitochondrial variation in populations of the ectoparasitic mite Spinturnix myoti with the genetic pattern of its host, the Maghrebian bat Myotis punicus in North Africa and in the islands of Corsica and Sardinia. Mite mitochondrial differentiation among populations was correlated with both host mitochondrial and nuclear differentiation, suggesting spatial co‐differentiation of the lineages of the two interacting species. Therefore our results suggest that parasite dispersal is exclusively mediated by host movements, with open water between landmasses as a main barrier for host and parasite dispersal. Surprisingly the unique presence of a continental European mite lineage in Corsica was inconsistent with host phylogeographical history and strongly suggests the former presence of European mouse‐eared bats on this island. Parasites may thus act as biological tags to reveal the presence of their now locally extinct host.